Bearings and method of making them



Feb, 17, 1931. H. L. BARTON 1,792,565

. BEARINGS AND METHOD 0F MAKING THEM Original Filed Deo. 12, 1925 5 Sheets-Sheet 1 A v 1 nu l 'l f/ [6j Il 3mm/Mofo -Feh 17, 1931. H; L BARTON 1,792,565

BEARINGS AND METHOD oF MAKING THEM original Filed Dec. 12, 1925 5 sheets-sheet 2 I Feb. 17, 1931. y BARTON i 1,792,565

BEARINGS AND METHOD OF MAKING THEM Original Filed Dec. l2, 1925 5 Sheets-Sheet 3 l P I I 1,4 l. l

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Feb. 17,1931. H. LJBARTON 1,792,565

BEARINGS AND METHOD OF MAKING THEM Original Filed Dec. l2, 1925 5 Sheets-Sheet 4 WAM gnucuhw Feb. 17, v.1931. H, L BARTON 1,792,565

BEARINGS AND METHOD OF MAKING THEM Original Filed Dec. 12. 1925 5 Sheets-Sheet 5 Patented Feb. 17, 1931 UNITED STATES PATENT 1ol-Flclez- HENRY L. DARTON, OF DETROIT, MICHIGAN, ASSIGNOR, BY MESNE ASSIGNMENTS, TO GENERAL MOTORS RESEARCH CORPORATION, OF DETROIT, MICHIGAN, A CORPO- RATION 0F DELAWARE BEARINGS AND METHOD OF MAKING- yTHEIII Application filed December 12, 1925, Serial No. 75,078. Renewed December 1, 1930.

This invention relates to bearings of the type used in automobiles to receive the journals of the crankshaft and similar rotating parts. These bearings are provided with a lining of soft metal, usually a Babbitt alloy, to reduce friction. In the manufacture of such bearings it has been found diiicult to secure a good bond between the lining and the metalof the back, and, as a result, the percentage of bearings which had to be rejected because of defects in bonding was very high. Furthermore, many of the bearings which Weresufiiciently good to ass inspection were found to possess so im er ect abond as to p resent the possibility o separation Ofbearmg and back and also interfere with the proper conduction of heat away from the bearin surface with the result that the bearing woul lbecome very hot rendering lubrication ineffective. Thus a microscopic examination of a number of approved bearings produced by the current method of casting the .babbitt in the back has revealed that the back and lining were bonded at widely separated points only. i

Not only have bearings roduced by prior processes frequently been ound to be defective but the methods of making them have been very complicated involving va great number of expensive machining operations and entailing ay great waste of materials.

I have devised a method ofl makin bearings which is verysimple-and by Whic bearings can be produced with a minimum of scrap. A bearing produced by my method is marked by a dense molecular structure enabling it to more effectively resist wear and by the very good bond which exists between the soft bearing metal and the back, giving very good heat conductivity.

My method consists in applyin soft bearing metal to the back by the use o very great pressure, say of the order of 125,000 pounds per square inch. lThis results in spreading the metal uniformly over the backand causing it to unite with the-back which has preferably been given a preliminary treatment, as by tinning, to facilitate bonding. In case 1t is found desirable or necessary to use a press of smaller capacity I may apply heat to the of heat is merely auxiliary to the use of pressure.. Where heat is used I have found pressures in the neighborhood of 70,000 pounds per square inch in combination with temperatures in the neighborhood of 350 F. to produce satisfactory results. I have also used pressure as low as 50,000 ,pounds per square inch and as high as 100,000 pounds per square inch and temperatures as low as 200o F. with good success.

. The resulting bond between the metals has been found to be much superior to that produced by previous methods for While bearings lined by prior processes have been found to possess a good bond at widely separated points only, bearings produced by my process have been found to possessa good bond surface.

.My process is capable of manymodifications in detail, but the manner inwhich I prefer to carry it jout is as follows: A blank is cut from flat stock, such as sheet steel, brass, or bronze. of a bearing segment in a suitable press. This operation may be performed in two steps, first, a` preliminary bending and then a bending to nal radius. The last o eration ircludes' a blow -upon a portion of t e blank to insure its set in final form. This pressing yor stamping operation ispreferably carried to the o int where the blank assumes final dimensions not only as to interior and exterior diameters but at the parting line as well. This can best be done by using blanks of a particular weight as in coining operations. However, if preferred, the press may be used for producing the desired curvature onl)T and This blank is formed to the shape a separate breaching operation ma be employed to shape the parting line. he blank thus formed is tinned and placed in a die in a press and the exact amount of powdered babbitt required for the bearing is placed in it. While a mixture of powdered Babbittv ingredients may be used and the pressure relied upon to alloy the mixture as well as .securefit to the bearing back, I have securedbetter results by the use of finely comminuted Babbitt alloy, the comminution preferably being done by atomizing babbitt while in a molten state. The die is of such shape as to prevent the escape of the babbitt when the plunger isbroughtdown so that the alloy is spread in a thin layer-over the surface of the bearing and formed into a dense' homogeneous structure well bonded to the back. At

volves but two essential operations, shaping ressing the babbitt into the blank. In ad ition, there may be not to exceed three or four'finishmachining operations.

the blank and This is to be contrasted with the fifteen or more operations required by former processes. The only waste of materials in my process is that involved in the finish machining operations and is very slight com` pared with the waste involved in the many rough shaping as well as finishi'n operations employed in presentpractices. y my process the vvery considera ble waste resulting from rejection of imperfect bearings is also practically eliminated. 4

It must be apparent that this process is capable of man -modifications; thus the bearing back nee not be formed of fiat metal stock as described, but ma be formed in any other desired manner. sired, be provided with grooves or the like so as to effect a mechanical interlocking of the back and lining in addition to the bonding previously, mentioned. The babbitt used for the lining may be solid, powdered, or a mixture of powdered Babbitt ingredients, lalthough I have rhad the greatest success when using powdered pig babbitt as described. When a mixture of powdered Babbitt ingredients is employed it may also be desirable to heat the bearingI after being pressed to per-` fect the alloy. -n some vcasestinning of thek blank may be dispensed with, although I have found tinning to be very desirable for the production of a good bond with the pressures Y which I have used. y It may be found 'desirable in some cases to provide relief passages in the die or plunger T e back may, if de-4 to receive excess metal as is customary 'in drop forging. In such event a separate cutting matic views showing the steps in the shaping ofthe blank. Y

, Figure 4 is a view, also somewhat diagrammatic, of a two-stage press which may be used to perform the operations shown in igures 2 and 3.

Figure 5 is an end view of the formed blank. y Figures 6 and 7 are diagrammatic views illustrating the method of applying the Babbitt lining to the back.

4Figure 8 is a perspective view showing the finished bearing. Figure 9 is a side elevation of the press emplo ed in the babbittin operation.

. ligure'lO is a view s owing the die or bed portion of the press. t

Figure 11 is a view taken on line 11-11 of Fi re 9. e

igure 12 is a View in elevation of the plunger portion of the press. Y

Figure 13 is a View of the plunger portion of the press taken on line 13-13 of Figure 9.

Fi ure V14; is a view of a magnetic mandrel.

whic may be used where a finishing operation is required in producing very accurately sized bearings.

In so far as my method of babbitting is concerned it is immaterial how the back be manufactured, thus itgmay consist of a portion of a cast tubular blank machined to proper shape, or the back may be an integral partof a connecting rod where the die is vof proper -shape to receive it. However, I pre-4 'fer to form the back from a blank 2 such as .Figure 2, in which it is subjected to a preliminary bending operation, the plunger 4 y"forcing the lblank into die 6. The blank is preferably so selected that the flow lines of the metal follow the curvature of the blank.

Ablank to a second bending operation illusl lil trated in Figure 3. In this figure the reference character 8 indicates the die and the reference character 10 the plunger. The plungeris provided with shoulders 12 which engage the edges or parting line of the partly formed blank 2 when the plunger is forced home. The shoulders exert a sufficient blow upon the blank to effectively set it in finished shape so that no subsequent machining of the blank is required. The die isy illustrated as open at its ends permitting the metal to be forced out at the ends as a result of the pressure. This makes it necessary to employ a straddle mill operation to reduce the blank to proper length. The blank shaping Voperation may be greatly facilitated by the provision of a blank of predetermined weight, the die in such case being preferably closed on all sides after the manner of the die shown in Figures 9 to 13, so that the How of metal must take place within a cavity of predetermined volume. By using blanks of a given weight they metal is properly distributed throughout the cavitycausing the blank to assume finished form and dimensions and at the same time effecting a very desirable densication of the molecular structure.

In Figure 4. I have illustrated somewhat diagrammatically a two-stage press Which A may be used for the operations illustrated in Figures 2 and 3. In this case the plunger 14 is provided with a die portion 16 for the preliminary bending and a die portion 18 for the final bending, the portion 18 being provided with shoulders 2O for the purpose previously described. These die portlons cooperate with the cavity in the die 22. y

Figure 5 is an end view of the formed bearing blank. It will be noted that the parting. line indicated by the'dotted line 24 coincides with a diameter of the bearing,a result produced by the action of the shoulders 12 upon the edges of the blank, the shape of which, prior to this operation, being shown in exaggerated form'at 26 in Figure 2. If shims are to be used, the parts of the die may be so designed that the parting line is parallel to a diameter instead of coincident with it.

Figures 6 and 7 illustrate diagrammatically the babbitting operation. In these figures, 28 is the' die and 30 the plunger provided with shoulders 32 for forming the parting line of the Babbitt lining. The die is shaped to conform exactly to the outside dimensions of the finished blank and as illustrated in Figures 9 to 13, confines the blank on all sides. AS shown in Figures 6 and 7, the die is provided` with shoulders 33 closely fitting the blank atthe.parting line to prevent the babbitt -from spreading'out over the ends of the blank. In

4general, the babbitting opera-tion consists in placing a predetermined quantity of babbitt in theback and subjecting it to very high pressure to cause it to Vunite with the back forming a compact wear resistin lining. In detail, I have found it best to tm the blank before the babbitting operation in order to insure a very good bond. If desired, the interior of the back may be grooved or otherwise roughened so as to effect a mechanical interlock between the babbitt and the back. However, I have found tinning alone to be very satisfactory. Where the term tinning is used in the claims it is of course to be understood to include any metal or substance used in effecting the bonding of the lining and back. v

Considerable variation is also permissible in the selection of bearing material. I have secured best results by the use ofA pig babbitt finely comminuted by atomizing it while in a molten state. However, 'if preferred, a mixture of powdered Babbitt ingredients may be employed, the pressure being relied upon to effect the alloying of the metals as well as the bonding of the lining to the back. IVhile good bearings may be produced by the use the back which is positioned in the die 28,'

the plunger 30 is forced home resulting in spreading of the babbitt in an even layer over the entire surface of the bearing and produring a very good bond between the babbitt" and the tinned back.

Figure 8 illustrates a bearing made by my process. The shaping operations performed on the blank gave to it substantially finished dimensions throughout. I-IoWever, if extreme accuracy is essential it may be necessary to broach or trim the parting line and in some cases to subject the outside of the blank to a. `slight grinding or other finishing operation.

However, for most purposes the bearing back assumes substantially finished dimensions as a result of the original forming and at the same time the molecular structure of the Vblank is greatly densified. It will be noted that this blank was also so selected that the flow lines of the metal follow the curvature of the blank thus reducing the possibility of fracturing the metal. The babbitt has been applied to the finished blankwith such great pressure as to produce a very good bond between thevlining and back over the entire surleo face of contact as contrasted with a bond at I have preferably provided means in coil- 'inore or less isolated spots which is the best nection with the plunger portion of mydie thatl can be roduced byv present processes. to prevent forcing of the sliding block 46 As a result t e heat-conductivity at the area out of position during the operative portion of contact or joint between the metals is renof the stroke of the plunger. This means dered very high and indeed actual test has preferablyl consists of a forked sto member` shown this conductivity to b as great as that 62 securedto the plunger portion o the press through the metals themselves. The treinen and] adapted to straddle the `part 52 and enclous pressure -us'ed in the babbitting operagage the end of the sliding block 46 to pretion also results inA thezproduction of a very vent its being forced out of position upon hard glassy bearing surface and in the densithe doWn stroke of the plunger. lication of the Babbitt lining and also, to a The plunger portion of the press comprises slight extent perhaps, iii a further densiiicathe usual part 64 which engages the babbitt tion of the bearing back. Q' andy forms it to the.,4 required shape. The

The babbitting operation is capable of plunger portion also carries blocks 66 prosome modification. As previously stated, it lvided with studs 68 having their upper ends may be desirable to apply heat to the die to guided iii cavities 70 formed in the plunger facilitato the forming operation, tcmperaportion and containing springs 72d adapted to tures around 350 being used in combination react against an enlargement formed on the with pressures in the neighborhood of 70,000- d part 68 to yieldingly force the blocks in a pounds per square inch. In. any .event tbe downward direction. The blocks 66 engage application of lheat is merely auxiliary to. the bearing segmentat the parting line before the use of pressure and the degree of heat the part 64 exertsappreiable pressure upon should be less than that required for the the babbitt and as the plunger is forced furlleltilig the tin 0r bablllil', aS tlllS plOCeSS ther 'down springs 72 are compressed and an is to he clearlyidistinguished from die caSt-4 eective seal is provided between the blocks ing or similar methods in which the 'metals 66 and the edges of the segment, thus prevent- {lle treated ln il. mOlteIl CODd'ltlQIl. .If (leSlled, ing any 0f the babbitt from being forced ont() also the plunger portionof the press may be the pertin line,

provided' with ribs or projections to forin It will apparent that the die is s0 arthe customary oil grooves and ilpql'tles .111 ranged as to enclose the'bearing on all' sides. the bearing and in some cases with relief The segment is a bearin fit in the cavity grooves as in die casting although this latter 43 inb10ek42, One endo the cavity is closed is objectionable in that subsequent trimming by fixed b10ek 44, the ether end bein dosed of the blank is made necessary. by sliding block 46. B-locks 66 covert e part- Figures 9 to 13 illustrate a. speclal press in which has been developed for the babbtting tion 64 is forced home the babbitt is of necesoperation. In these figures, 40 indicates the sity compressed into a thjn layer evenly bed plate on which the die iS Securd- T hiS spread over the interior-.of the blank. The die CODSSS essentially 0f a block 4 2 halhg reference character 69 indicates resistance elea semi-cylindrical cavity 43 therein of the ments which may be provided in the die and exact shape 0f the lgelllng 011e end A plunger lfor heating the parts when desired. of this semi-cylindrical cavityl is closed by While aspreviously stated the bearing is means of a block 44 Xed fithebled Plat@ now finished for all practical purposes, yet if While' the Other, end, is closd by Sliding eXtreme accuracy is desired the blank may be block 46 operatingr in, a guideway betweenk WO fixed blOCkS 4:8. blOCk machining preferred, 'the exterior ma..

iS DIOVfl-efl with@ cavity 50 t0 receive 0h@ chinin may be done prior to the babbitting end 0f a SPlh' Tetlhcted plunger 52 Operated operat on. I have illustrated in Figure 14 by means ot a shaft 54 having an eccentric a Special magnetiema'drel which may be 56 tbcreml'llud PIOVKld Wllh ah 0PI`at1h2.used 'for .theexteriorlinishing operation handle 58. 1110119 T )Qsltloh' 0f the, handle, 58- where a steel back bearing is produced. This the ShdmL block 46 1S held firmly m posltld mandrel consists essentially of a shaft 80 of by the plunger 52 to close. one end of the die magnetic material of a Size to receive a pail. cavity a-nd in the other position of the handle of .finished blanks or benin se, ents 58 the plunger is retracted relievingtheblock U 'on the shaft ismounted anectrol; et; ot pressure so as to facilitate the ejection of 'QPwhich may b'e energized from any suitzle the finished bearing from the die by the operv ation of the lknockout rod 60. If the block source to hdd the beanng Parts Securely uP0n t e shaft. I have shown at 84 a conven- 46' were fixed the heavy pressure exerted might result in wedging thebearingseqment tlonal grinding Wheel. which may be Sed for in the die cavilyso that upon operation of the fnShhg'OPeltiQn- {.Ifdesiled, any suie' the knockout rod 60 the bearing segment ,able 11108115 Sllh as P111 01 Screw bOlt 86 vwould be subjected to some distortion. Bv may be used to prevent rotation of the seg- 'the meansdescribed this diiculty is obviated. ments about the shaft during the grinding g line of the blank. When the plunger pol- 4 broached interiorly and subjected to outside tin, said lining but I have found in actual practice that this is unnecessary.

1. A bearing consisting of a bearing back and a lining of soft bearing metal secured thereto in good heat conducting relation, said lining having a dense homogeneous structure produced by the union of finely divided par-v ticles of bearing metal with each other and with the bearing back under very high pressure.

2. A bearing consisting of a bearing back, a coating of tin on said back and a layer of babbitt overlying said tin, said layer being composed of finely divided particles of babbitt secured to the back in good heat conducting relation by means of heavy pressure.

3. A bearing consisting of a back pressed out of sheet metalhaving a coating of tin thereon, and a lining of babbitt overlying the consisting` of finely divided particles of powdered Babbitt alloy secured to the back in good heat conducting relation by heavypressure.

4. The method of making a bearing which consists in providing a bearing back, placing a quantity of powdered bearing metal in the back and applying pressure to the powder to cause it to unite with the back in good heat conducting relation.

5. The method of making a bearing which consists in providing a bearing back, tinning the back, placing the back in a suitable die, putting a quantity of powdered bearing metal in the back andapplying heavy pressure to the metal to cause itlto unite with the back in good heat conducting relation. l

6. The method of making a bearing which consists in providing a bearing back, tinning the back, placing the' back in a suitable die which is closed on all'sides, placinga quantity of powdered babbitt in the back, and applying pressure to the babbitt to cause it to unite with the back in good heat conductingrelation and to cause the bearing to assume substantially finished dimensions.

7. The method of making a bearing which consists in providing a bearing back, tinning the back, placing the back in a suitable die which is enclosed on all sides, putting the exact amount of powdered soft bearing metal in the back which it is desired to secure thereto; and applying pressure to the metal to cause it to unite with the back'in good heat conducting relation, and to cause the bearing to assumefinished dimensions.

8. The method of producing a Babbitt lined bearing which consists in taking a bearing back, tinning the back, placing the back in a suitable die, placing in the back a quantity of powdered Babbitt alloy and applying. pressure to the babbitt to cause, it to unite with the back in good heat conducting relation.

9. The method of producing a Babbitt lined bearing which consists in taking a bearing back, tinning the back, placing the back ing in the die the exact amount of soft bear ing metal which it is desired to secure to the back, and applying heavy pressure. to the soft bearing metal to secure it to the back in good heat conducting relation.

11. The method of making lined bearings which consists in tinning a bearing back, placing it in a die which is substantiallyclosed on all sides, placing in the back the exact amount of babbitt which it is desired to secure to the back, and applying pressure to the babbitt to secure it to the back in good heat conducting relation.

12. The method of making a bearing which consists in taking a suitably shaped blank, pressing it to substantially finished dimensions, tinning the formed blank, ,placing the formed blank in a suitable die, putting a quantity of powdered babbitt in thel die, and' applying a high degree of pressure to the babbitt to cause it to unite with the back in good heat conducting relation.

13. The method of making a bearing which consists in taking a suitably sha ed blank, pressing it to substantially nis ed dimensions, tinning the formed blank, placing the formed blank in a suitable die, putting in the Jformed blank the exact amount of powdered Babbitt alloy which it is desired to secure lto the back and applying pressure to the babbitt to cause it to adhere to the back in good heat conducting relation and to cause the bearing to assume Afinished interior dimensions.

. 14. A bearing comprisin a tinned steel back having a lining of soft bearing metal secured thereto, said bearing metal being in the form of finely comminuted particles secured to the back in good heat conducting relation by means of heavy pressure.

15. The method of making a bearing which lconsists in taking a back of predetermined weight, placing it in a die substantially closed on all sides and subjecting it to heavy pressure to form it to the exact shape and dimensions desired, placing a predetermined quantity of finely comminuted beam ing metal in the back and pressing it to cause it to adhere tothe back and to assume substantially finished shape and dimensions.

16. The method of making a bearing back which consists in taking a back of predetermined weight, lacing it in a die substantially closed on a sides and subjecting ,it to heavy pressure to form it to the exact shape and dlmensions desired, tinningA the back 5 and placing a predetermined quantity of nely comminuted pig Babbitt metal in the back and coin pressm it tocause it to unite with the back 1n goo heat conducting relation and to assume' substantially finished lo shpe and dimensions. n testimony whereof I aix my si ature.

HENRY L. BAR N. 

